Creaky Chassis 1999 LS

We just purchased a 1999 Malibu LS, 87,000km. Love the car but notice that the back half of the car and the front passenger side creaks badly(for lack of a better word), especially at slower speeds. The entire car, interior, exterior and under the hood still look like new. Previous owners were extremely kind to this car. There is no evidence of body work or replaced parts. Any suggestions? Thanks.

big problem with front and rear upper strut mounts with these cars, start there first.

Acemech129,
Thanks for the suggestion. I'll get it checked out next week.